Even though there are a million pigeons in the city. you never see a baby pigeon. it makes you wonder where they are hiding out. any with the fragment?

The fragment here is that the sentences are being punctuated as if they are complete sentences (which they aren't). 

One way you can fix this fragment is: Even though there are a million pigeons in the city, you never see a baby pigeon. 

Another way is: You never see a baby pigeon even though there are a million pigeons in the city.